1. Field of the Invention
This invention relates to an apparatus for collating sheet like elements and more particularly to an apparatus for collating envelope blanks in underlapped relation for application of sealing adhesive to the marginal edges of the seal flap left exposed between adjacent envelopes.
2. Description of the Prior Art
The application of gumming adhesive to a marginal area of the seal flap of an envelope by conveying individual envelope blanks from a fast moving mechanism to a slow moving mechanism for arranging the blanks in a staggered or lapped relation to permit continuous application of a gumming adhesive by a roller applicator to the marginal edges of the blanks is known, as illustrated in U.S. Pat. Nos. 3,141,667; 3,096,977; 2,918,278; 3,479,025 and 3,672,667. U.S. Pat. No. 2,782,898 provides a mechanism for collating envelope blanks by transferring the blanks from a fast conveying means onto a slow conveying means positioned at a lower lever to thereby prevent interference between the slow advancing trailing edge of a blank with the faster advancing leading edge of the next following blank. A resilient paddle wheel disposed between the conveying means engages the blanks as they leave the bight of the faster conveyor providing continuous travel of the blanks at the fast linear speed to the lower plane where the blanks are engaged by the slow conveyor.
The paddle wheel maintains the traveling blank at the fast linear speed until the forward edge of the blank engages the rollers of the slow conveyor. The trailing edge of the slow moving blank then falls clear of the fast moving leading edge of the succeeding blank which then is thrust into the feed bight of the slow conveyor. With this arrangement the succeeding blank overlap moves at a higher relative speed into overlapped relation with the preceding blank subsequently engaged in the feed bight of the slow conveyor. In the collating of formed envelopes having window patches secured thereto, relative movement between successive envelopes in lapped relation frequently results in the hooking of window patches by the following edge of the preceding envelope to skew the entire stream of envelopes.
U.S. Pat. No. 1,681,162 discloses a delivery apparatus for printing presses arranged to separate newspapers into unit piles coming from a press. The printed papers are initially folded and collected for delivery between a pair of overlying fold-laying rollers which direct successively moving folded papers downwardly along the face of a plurality of guide bars. The papers advancing downwardly along the faces of the guide bars are discharged into slots between adjacent arms of a plurality of rotary fly devices. The rotary fly devices rotate in a clockwise direction and deliver successive papers one at a time upon the delivery belts providing for relative movement of adjacent papers as they are transformed from a continuous spaced stream to a stacked relation on the belts.
A kicker device traveling on the surface of a cam which revolves in timed relation to the fly device and fold-laying rollers are arranged to contact the advance edge of the paper being carried downwardly and toward the left of the fly device. Contact with the paper edge moves the paper out of engagement with the fly device projecting the paper forwardly in advance of the position which the paper would otherwise have had upon the pile of papers on the belt. With this arrangement, the kicker device changes the position of one paper without changing the position of adjacent papers. Preferably, the kicker is actuated twice at each rotation of the cam to thereby change the position of one paper for every fifty papers received upon the belts to provide for separation of the papers in unit piles.
In U.S. Pat. No. 3,116,668, an envelope folding and delivery mechanism performs the operations of folding and adhering of the bottom flap of an envelope blank, folding of the dried seal flap, and delivery of the finished envelopes one by one into stack formation. The spaced out envelope blanks are transferred with the bottom flap leading and the seal flap trailing from a first suction drum to a second suction drum where the fold along the bottom flap is initiated as the blank advances over the drum. A continuously rotating pressure roller picks up the bottom flap of the blank released by the second suction drum and folds it over the body portion of the blank. Suction means on the second drum holds the leading margin of the seal flap portion to the drum while the body portion is folded over onto the seal flap portion. Thereafter, the folded blanks are discharged individually by the second drum at a relatively high initial rate of travel upwardly into the spiral slots of a comparatively slow revolving slotted carrier. The slotted carrier includes a plurality of overlapping curved slots which spiral inwardly in the direction of rotation of the carrier. The blanks are decelerated in the slots and are arrested by a stationary horizontal table which extends secant to the slotted carrier. The table acts to eject the blanks from the slots as the carrier continues to rotate downwardly. In this manner, all the blanks are stacked so that the lower edges are pressed against the table with the blanks arranged in a fully overlapped relation. As each envelope is added to the stack, the stack is pushed along the table by the carrier to the extent of the thickness of the added blank. The slotted carrier is not arranged to discharge the blanks from the surface of the table; consequently, the blanks come to a complete rest in a stacked relation.
U.S. Pat. No. 1,266,737 described an apparatus for directing a plurality of folded sheets in a first direction and then a plurality of folded sheets in another direction. The two bundles of sheets are then arranged into one pile in which the folded edges face in opposite directions. Initially, folded sheets are delivered by a pair of cylinders between two guides in a continuous stream. A pair of fans are positioned adjacent each other with their fan blades arranged tangent to the opening between the guides. The fans are supported for oscillating motion on shafts which are positioned in the side frame at different levels so that the blades of one fan may be arranged to receive folded sheets discharged from between the guides while the blades of the other fan are withdrawn from the path of the sheets. With this arrangement, the blades of one fan receive the folded sheets and deliver them to a conveyor in stacked relation, the succeeding sheet positioned upon the preceding sheet. Then after a predetermined number of sheets have been stacked, the first fan is withdrawn from the guide path and the other fan is oscillated into position to receive the sheets. The second fan revolving in the reverse direction of the first fan, delivers the sheets in reverse position upon the stack of sheets positioned beneath the blades of the first fan. When the desired number of sheets have been stacked, an elevator removes the bundle for further processing.
There is need for an envelope collating mechanism that does not require elaborate apparatus to efficiently reduce the speed of the individually conveyed envelope blanks for orderly arrangement in lapped relation for further processing. Further, there is need for a collating apparatus which arranges successive blanks in a lapped relation without necessitating relative movement between blanks as they are positioned in lapped relation.